One easy way to stream audio on the web is to use the Shoutcast plugin for Winamp. You'll need a server, which you may have to pay for, but it doesn't involve actually streaming using a webpage. What you could do is use a Shoutcast server to stream your music, and simply put a link to the stream on your webpage.

Click HERE (http://www.shoutcast.com/download/broadcast.phtml) to download what you need.

I'm sure there are many other ways of streaming audio on the internet if this isn't quite what you're looking for.